The invention relates to a fire-retardant sheet element with at least two transparent fire protection glass plates, which abut one another at lateral edges, wherein these glass plates comprise at least two glass panes disposed parallel and spaced apart and a fire protection layer between these glass panes, and between the abutting lateral edges of the glass plates a sealing configuration is installed.
Fire-retardant sheet elements of this type serve for the purpose of closing openings in buildings, for example wall breakthroughs, or they serve as partition or delimiting elements for rooms. Transparent fire protection glass plates or fire protection glasses correspond in known manner to the requirements, for example of the German Standard DIN 4102. A known fire protection glass comprises, for example, several silicate glass panes disposed parallel and spaced apart from one another, between which a fire protection layer is interpolated. In the event of fire, upon reaching a certain temperature this fire protection layer foams up and, laminated with the glass panes, forms a thermally insulating structural element.
For reasons of strength and also of production technology, it is not possible to fabricate fire protection glasses of any desired dimensions. To produce large-area, fire-retardant and transparent sheet elements, it is known to join two or more fire protection glass plates in a common surface to form a sheet element. The discrete fire protection glass plates are therein positioned and held against one another with the aid of connecting elements, for example frame parts. Corresponding connecting elements are also necessary in the transition region between the fire protection glass plates and the adjoining elements of the building or structural parts. Such connecting elements or frame structures for joining fire protection glass plates with the surrounding structural elements are known, for example from DE-U-80 24 086 and DE-U-71 48 693. DE-U-80 24 086 discloses placing a fire protection glazing in a fire protection door. A fire protection glass plate is therein fastened with the aid of Z-shaped frame profiles on the structural part, or on the door. In the gap between the edge regions of the glass plate and the structural parts coatings are disposed which are comprised of a thermal insulating material, in particular containing water glass, with the capability of foaming under the action of heat. These coatings seal the gaps in the event of fire. DE-U-71 48 693 describes the mounting of a fire protection glass plate in a metal frame, for example a door. The seal between the edge regions of the glass plate and the metal frame is therein formed such that in the event of fire a fire protection composition, disposed between parallel glass plates, foams and expands in the direction of the gap. Through the foaming material exuding from the glass plates the gap is sealed.
With buildings with large-area glazings, for example, building fassades, it is known to have glass plates abut one another at the edges without frame parts. The covering of the gap between two adjacent glass plates in this case takes place for example by covering and partially filling the gap with a silicone composition. When using fire protection glass plates, these techniques are used today only in isolated cases since there exists the prejudice that the joint and the sealing material must be covered with a frame element.
When joining several fire protection glass plates to form a sheet element, each of the individual fire protection glass plates abut at least with one lateral edge one adjacent fire protection glass plate. The mounting of fire protection glass plates in the region of two abutting lateral edges of adjacent plates can take place by means of known frames. But this leads possibly to esthetically undesirable wide frame profiles. Furthermore, there is also the known problem of thermal bridges, if these frame profiles are produced for example of metal. DE-U 91 06 478 reveals a solution which makes possible the formation of narrow frame profiles in the region of the abutting lateral edges without thermal bridges and reference is also made to the fact that the frame profiles can be omitted. According to this solution the penetration of smoke and flames through the partition gap between the lateral edges of adjacent fire protection glass plates is said to be prevented thereby that upon the fire protection glass plates becoming heated, the fire protection layer swells and penetrates into the gap between the lateral edges of adjacent glass plates and fills this gap. This entails the disadvantage that in the event of fire this gap is closed so as to be fire- and smoke-tight only after the swelling material of the fire protection layer penetrates into the gap region. Until a minimum temperature is reached which causes the swelling of the fire protection composition, the gap is open and, for example, smoke can penetrate through it. A further disadvantage lies therein that the known fire protection layers comprise materials, for example hydrated alkali metal silicate compositions, which, on contact with the atmosphere, change their structure and in time lose their capability to function. Consequently, the hazard exists in this configuration that the fire protection layer dries out or becomes discolored. In order to avoid this, bilaterial placement of frame profiles with corresponding seals is necessary.
The present invention addresses the problem of proposing a solution for fire-retardant sheet elements with at least two transparent fire protection glass plates, in which abutting lateral edges of adjacent fire protection glass plates are developed without frame parts, which completely seal fire protection layers, disposed between the glass panes of fire protection glass plates, against the ambient atmosphere and are protected, and the seal in the region of the abutting lateral edges of adjacent fire protection glass plates is fully effective immediately after the joining to form the sheet element, and is smoke-tight even below the activation temperature of the fire protection layer.
This problem is solved with the characteristics defined according to the invention. Advantageous further developments of the invention are evident based on the characteristics of the dependent claims.
The device according to the invention has the advantage that large-area fire-retardant sheet elements can be built of at least two fire protection glass plates, in which the lateral edges of the glass plates, which abut one another in the transparent region, are not covered by frame parts but are free of frames in this region. The fire protection layer, which is disposed between the glass panes of the discrete fire protection glass plates, is simultaneously protected along the edge region of the glass plates against contact with the atmosphere. For this purpose, the discrete fire protection glass plates are developed such that the fire protection layer between the glass panes, disposed parallel and at a spacing from one another, does not extend to the outermost edge region but rather along the margin region of the plate a groove is developed, which can have a depth of a fraction of a millimeter up to several millimeters. This groove is already developed at the time the fire protection layer is placed between the parallel glass panes or is worked into the fire protection layer after the fire protection plate is finished. This can take place for example through mechanical working or with the aid of a solvent. This groove in the fire protection layer between the margin regions of the glass panes is filled with a barrier material which protects the fire protection layer against contact with the atmosphere and connects the margin regions of two parallel disposed glass panes so as to be air- and vapor-tight. Suitable materials for filling this groove are elastic polymers, preferably polysulfide. The abutting lateral edges of two adjacent fire protection glass plates are disposed with respect to one another at a spacing of at least one millimeter such that between the lateral edges a gap is generated. Into this gap is introduced a sealing configuration, wherein according to the configuration according to the invention several implementations are possible. The sealing configuration extends over the entire length of the interspace or the gap between the lateral edges of adjacent fire protection glass plates and is built of at least one, preferably several, sealing elements. An especially simple solution is obtained by placing into the gap between the lateral edges of adjacent fire protection glass plates a preformed elastic sealing profile. The sealing profile therein extends through the entire cross section of the gap between two glass plates and largely fills this cross section. The sealing profile therein comprises in known manner a heat or fire-resistant material from the group of polymers, preferably a natural unvulcanized rubber, synthetic rubber or silicone. Since the sealing element, or the sealing profile, does not need to fulfill any sealing function for the fire protection layer, its material can be optimally matched to the desired fire resistance. Since the seal extends through the entire gap, the additional advantage is obtained that the entire quantity of the material in the gap acts as a protective element. This yields a substantial improvement in the resistance time against fire. Covering the sealing element with frame parts is no longer necessary.
A further advantage is attained through a multi-part implementation of the sealing configuration between the abutting lateral edges of adjacent fire protection glass plates. Into the gap between the abutting lateral edges of the fire protection glass plates an addition element is placed comprising a fire-retardant material. This material has at least the same fire-retardant effect as said polymer seal, preferably an even better effect. On the two sides directed toward the broad side of the glass plates, i.e. toward the two outsides of the gap, each of the addition elements is covered by one sealing element. This sealing element can therein be a preformed elastic sealing profile or the sealing element can be applied as a plastic composition. As plastic compositions are suitable elastomers, for example silicone rubber. An especially appropriate solution comprises placing as addition element a profile rod of hardwood into the sealing configuration or into the gap. The remaining residual region of the gap is filled with a silicone composition, for example GE Pensil 300 by General Electric Silicons. This silicone composition connects the abutting fire protection glass plates or their outer glass panes and seals the gap against moisture and air. It protects the edges of the glass plates and also the emplaced addition element. A further advantageous solution comprises placing as the addition element into the sealing configuration a profile rod of a material comprised of a water-containing silicate, for example Kerafix Blahpapier (Gluske GmbH). The sealing configuration with an addition element satisfies without frame elements all of the requirements of fire protection. Simultaneously, the fire protection layer in the glass plates is permanently and completely protected against outside influences.
With the device according to the invention it is possible to develop in sheet-form fire-retardant sheet elements frame-less joints between abutting lateral edges of fire protection glass plates, which are very narrow and are virtually invisible. This permits building esthetically optimally implemented transparent sheet elements, wherein simultaneously a high fire-retardant effect or fire resistance is attained. With the configuration according to the invention it is possible to build, for example, fire-retardant sheet elements which meet the requirements made of F30 glazings according to DIN 4102. The sheet element is already smoke-tight in the normal state, i.e. when the fire protection glass plates are cold. For the connection of the surrounding structural element, or structural part, and the sheet element of glass plates, frame structures known per se are employed. These known frame structures can be combined in simple manner with the sealing according to the invention of the abutting lateral edges of the fire protection glass plates. It is also possible to seal the gap between an edge of a glass plate and the adjoining structural part, for example a wall, according to the devices of the invention.